If we take the time to see the transformation of door locks from the mechanical key operated, to electrified locksets, to standalone battery operated locks and finally to networked battery operated locks, we can get a better understanding of how each of the locks operate, their features and conveniences. A number of these features have created significant opportunities for controlling access. Many have become required standards for end-users including audit trail and time-date capabilities.
Locksmiths have installed, keyed and serviced mechanical cylindrical and mortise locks that include the Kwikset 400BDL, National E-Z Set, Sargent 8 Line and 8100 Series, Schlage D/ND Series and K/L Series, and Weiser A500 Series. These residential and commercial grade cylindrical locks could be rekeyed by removing the knob, pull the tail shaft and rotate plug, or popping out the cylinder assembly to name three of the more common lock cylinder removal methods. We learned how to service these and other locks and even had to read the instructions on a few of them.
Mechanical locks have basic locking methods. A key is required to unlock the lock. Some locks require a key to lock them. Over time, master keying techniques expanded and provided greater opportunities for controlling physical access. In addition, clever locksmiths and lock manufacturers developed different types of locks and keys to further control access. These included double cylinder lock cylinders, key trap lock cylinders, one way lock cylinders, construction keys and specific applications for mortise and cylindrical locks. However, someone still had to insert the proper key into the lock in order to gain access.
The first electronic access control devices were introduced in the 1980s. Mortise locks were electrified using electromechanical solenoids to power the latch mechanism by aftermarket re-manufacturers such as Architectural Control Systems Inc., Command Access, Marray and the lock manufacturers themselves. To operate these locks, an external power source, a switch and wiring were required. The switch in some of the early installations was a doorbell button and the power supply a simple transformer.
These early electrified locks provided the end users with a method to remotely control access. The front door could remain locked and someone did not have to physically go to the door in order to provide access. The person, sometimes a receptionist or secretary, would have to press a momentary button to temporarily unlock the lock. Some of the early installations were jewelers, travel agents and businesses in questionable neighborhoods.
Over time, the current draw and the size of the electromechanical solenoids improved. As solenoids became small enough, cylindrical locks became available electrified. Electrified locks are available with Fail Safe and/or Fail Secure electromechanical solenoids.
This choice determines the condition of the lock mechanism. A Fail Safe operation electromechanical solenoid unlocks the door lock and a Fail Secure operation solenoid keeps the door locked when power is turned off. More important are the door monitoring capabilities, which include REX (Request to Exit), latch and deadbolt monitoring, lock cylinder monitoring and door position monitoring capabilities. The features depend upon the lock manufacturer and the model.
The first standalone (without wires) battery operated electromechanical lock was introduced in the late 1980s with a number of other lock manufacturers introducing their models. The inclusion of a circuit board-equipped lock provided many new ways to control access. These battery operated locks did not require any external wiring, external power source or multiple components for installation.
Over the years, a number of different function standalone, battery operated electromechanical locks have been developed. In addition to the cylindrical, mortise and exit device application, companies such as Adams Rite, Sargent and others have introduced their version of the narrow and medium stile aluminum/glass door compatible locks that are designed to operate the Adams Rite style of deadbolts and deadlatches.